1. Field of the Invention:
The present invention relates to a fuel injection system for injection carburetors which adjusts fuel injection rate adequately on the basis of negative pressure produced dependently on air flow rate.
2. Description of the Prior Art:
The fuel injection system of this type has already been disclosed, for example, by Japanese Preliminary Patent Publication No. Sho 63-5150. This conventional fuel injection system is adapted to control flow rate of fuel to be injected into a suction tube through a fuel jet from a fuel chamber so as to balance fuel pressure downstream the fuel jet communicated with the fuel chamber with negative pressure produced in the venturi by arranging a regulator consisting of a depression chamber and a fuel pressure chamber which are divided by a diaphragm, and by introducing negative pressure from the venturi arranged in the suction tube into the depression chamber of the regulator.
This conventional fuel injection system comprises a long fuel passage from the fuel pressure chamber to the fuel nozzle, thereby posing problems that ignorable time lags are produced between variation of flow rate of the air flowing through the suction tube and variation of flow rate of the fuel injected through the fuel nozzle, and that the fuel injection system itself has a complicated structure.